The Korean government considers expanding the WtE share of total energy from 1% to 5% by 2020 through research and development (R&D) in waste-to-energy (WtE) technologies. This study attempts to measure the external benefits of investing in R&D in these technologies. To this end, a contingent valuation (CV) is employed. More specifically, a 2016 national survey of randomly selected 1,000 households was carried out across the nation to gauge the willingness to pay (WTP) for the investment. One-and-one-half-bounded dichotomous choice question was used in the CV survey, and the spike model was applied to dealing with zero WTP responses. The mean yearly WTP is estimated to be KRW 4,175 (USD 3.57) per household, which is statistically significant at the 1% level. Expanding the value to the entire nation translates into an investment of about KRW 79.1 billion (USD 67.6 million), which can be interpreted as the annual external benefit of the R&D investment in WtE technology.